Technical Field
The present disclosure relates to a brushless motor.
Related Art
A conventional outer rotor type brushless motor provided with a motor shaft, a rotor housing rotatably supported on the motor shaft through a shaft bearing, and a stator housed inside the rotor housing is known (for example, see Japanese Patent Application Laid-Open (JP-A) No. 2014-36525).
In such brushless motors, the performance of the shaft bearing is liable to decrease when exposed to water due to water droplets having penetrated through to the inside the rotor housing. A brushless motor provided with a labyrinth structure has therefore been proposed for suppressing the shaft bearing from being exposed to water (for example, see JP-A No. 2007-53844).
Amongst brush motors of this sort, there are also motors employed as vehicle fan motors (for example, see JP-A No. H09-261915). This vehicle fan motor is fixed to the vehicle body by a shroud. A fixing portion provided at a central portion of a fan is fixed to a rotor housing in this fan motor, and the fan rotates together with the rotor housing.
However, in the vehicle fan motor described above, penetration pathways for water droplets are liable to arise at gaps in an outer peripheral portion of the fan motor, namely, at gaps formed between the rotor housing, the fixing portion of the fan, and the shroud. Thus, a labyrinth structure configured by the rotor housing, the fixing portion of the fan, and the shroud could conceivably be provided at the outer peripheral portion of the fan motor in order to prevent penetration by water.
However, in such cases, flow of cooling air that cools a winding coil section wound around teeth of the stator and that is expelled toward the radial direction outside of the fan motor is liable to be hindered by the labyrinth structure. Accordingly, it is desirable to secure cooling of the winding coil section while suppressing the shaft bearing from being exposed to water.